Fibronectin and coagulation factor XIII increases blood platelet adhesion to fibrin.

Fibronectin is covalently linked to fibrin during clot formation by coagulation factor XIII and has been suggested as a possible mediator of platelet adhesion to collagen. Fixed human platelets were found to adhere to fibrin. This adhesion was significantly increased when fibronectin was incorporated into the fibrin network, and was supported by factor XIII.